Why do you need to reverse a PHP array?

PHP Array reversal has the following uses: getting the last element, traversing in reverse order, and creating a descending array. There are two methods of reversal: 1. array_reverse() function; 2. Use for loop. For example, to print a student resume in reverse order: first use array_reverse() to reverse the array, then traverse the reversed array in reverse order, outputting the name, age, and skills of each student.

#Why do you need to reverse a PHP array?

In PHP, array reversal is very useful in the following situations:

• Get the last element: The last element of the array can be reversed by Convert an array to get it easily.
• Traverse in reverse order: Reversing the array can conveniently traverse the array elements in reverse order.
• Creating a descending array: Reversing an array creates a descending version of a sorted array.

Two methods to reverse PHP array

1. array_reverse() function

<?php
$arr = [1, 2, 3, 4, 5];

// 反转数组
$reversed_arr = array_reverse($arr);

// 打印反转数组
print_r($reversed_arr);
?>

2. Using a For loop

<?php
$arr = [1, 2, 3, 4, 5];

// 创建一个新数组来存储反转后的元素
$reversed_arr = [];

// 使用 for 循环倒序遍历 original 数组
for ($i = count($arr) - 1; $i >= 0; $i--) {
    // 将元素添加到 reversed 数组的开头
    array_unshift($reversed_arr, $arr[$i]);
}

// 打印反转数组
print_r($reversed_arr);
?>

Practical case

Print students’ resumes in reverse order

// 模拟学生履历表数组
$students = [
    ['name' => 'John', 'age' => 21, 'skills' => ['PHP', 'JavaScript']],
    ['name' => 'Jane', 'age' => 22, 'skills' => ['HTML', 'CSS']],
    ['name' => 'Bob', 'age' => 23, 'skills' => ['Java', 'Python']],
];

// 使用 array_reverse() 反转数组
$reversed_students = array_reverse($students);

// 倒序遍历反转的数组
foreach ($reversed_students as $student) {
    echo "Name: {$student['name']}, Age: {$student['age']}, Skills: ";
    foreach ($student['skills'] as $skill) {
        echo "$skill ";
    }
    echo "<br>";
}

This code will print the student's resume in reverse order:

Name: Bob, Age: 23, Skills: Java Python
Name: Jane, Age: 22, Skills: HTML CSS
Name: John, Age: 21, Skills: PHP JavaScript

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